We next calculated the mean expression values across individuals and visits for each overlapping detected probe between four pairs of cell and RNA isolation methods with (partly) corresponding or closely related cell types to visualize inter-individual variability: i) PAX and PBMCs, ii) LCLs and B-cell CD19, iii) LCLs and B-cell CD20, and iv) B-cell CD19 and B-cell CD20 (Figure 2). The PAX expression levels are decreased but more variable than the PBMC expression levels (ρ = 0.85). The LCL expression levels are of similar magnitude as the B-cell CD19 or B-cell CD20 expression levels (ρ = 0.83 and ρ = 0.79 respectively) but lower than the correlation between B-cell CD19 and CD20 (ρ = 0.98).
